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Implementation of a model for identifying Essentially Derived Varieties in vegetatively propagated Calluna vulgaris varieties.

Borchert T, Krueger J, Hohe A - BMC Genet. (2008)

Bottom Line: In contrast, the system applied in lettuce, which itself applies pairwise comparisons using appropriate reference sets, proved functional with this species.The narrow gene pool detected in C. vulgaris may be the genetic basis for juridical conflicts between breeders.We successfully tested a methodology for identification of Essentially Derived Varieties in highly identical C. vulgaris genotypes and recommend this for future proof of essential derivation in C. vulgaris and other vegetatively propagated crops.

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Affiliation: Heidepflanzen Peter de Winkel, Douvenberg 34, 47547 Goch, Germany. borchert@erfurt.igzev.de

ABSTRACT

Background: Variety protection is of high relevance for the horticultural community and juridical cases have become more frequent in a globalized economy due to essential derivation of varieties. This applies equally to Calluna vulgaris, a vegetatively propagated species from the Ericaceae family that belongs to the top-selling pot plants in Europe. We therefore analyzed the genetic diversity of 74 selected varieties and genotypes of C. vulgaris and 3 of Erica spp. by means of RAPD and iSSR fingerprinting using 168 mono- and polymorphisms. The same data set was utilized to generate a system to reliably identify Essentially Derived Varieties (EDVs) in C. vulgaris, which was adapted from a method suggested for lettuce and barley. This system was developed, validated and used for selected tests of interest in C. vulgaris.

Results: As expected following personal communications with breeders, a very small genetic diversity became evident within C. vulgaris when investigated using our molecular methods. Thus, a dendrogram-based assay to detect Essentially Derived Varieties in this species is not suitable, although varieties are propagated vegetatively. In contrast, the system applied in lettuce, which itself applies pairwise comparisons using appropriate reference sets, proved functional with this species.

Conclusion: The narrow gene pool detected in C. vulgaris may be the genetic basis for juridical conflicts between breeders. We successfully tested a methodology for identification of Essentially Derived Varieties in highly identical C. vulgaris genotypes and recommend this for future proof of essential derivation in C. vulgaris and other vegetatively propagated crops.

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Shoots of two C. vulgaris genotypes representing the main inflorescence types. left: normal ('White Mite'), right: bud ('Anneliese').
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Figure 1: Shoots of two C. vulgaris genotypes representing the main inflorescence types. left: normal ('White Mite'), right: bud ('Anneliese').

Mentions: Breeding efforts in C. vulgaris primarily aim at a special type of its inflorescence, the so-called bud flowers (Fig. 1). Flowers of these plants do not open during the entire reproduction phase from August to December which makes them appear visually attractive for a long period of time when not many other flowering ornamental outdoor plants are available in the northern hemisphere. This phenotype is closely linked with and possibly caused by a lack of anthers. This connection, in turn, has a severe impact on breeding methods because interesting bud-flowering genotypes are only applicable as the female parent in crossings. In addition, there is only sparse information and hypotheses available concerning the inheritance of this trait. Therefore – and since C. vulgaris is a vegetatively propagated crop – breeding in C. vulgaris over the past few decades was to a large extent performed by selection of spontaneous mutations, rather than by systematic crossings (personal communications with breeders). The actual variety composition in Europe offers a mixture of normal flowering and bud flowering types (state: 01/2008) with main focus on the latter (~85%). Some special forms (e.g. 'Radnor' with filled flowers or 'Peace' as a multi-bracteate type) are present as well. However, due to the problems described above, the actual gene pool used in breeding of C. vulgaris is presumably quite narrow.


Implementation of a model for identifying Essentially Derived Varieties in vegetatively propagated Calluna vulgaris varieties.

Borchert T, Krueger J, Hohe A - BMC Genet. (2008)

Shoots of two C. vulgaris genotypes representing the main inflorescence types. left: normal ('White Mite'), right: bud ('Anneliese').
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2536668&req=5

Figure 1: Shoots of two C. vulgaris genotypes representing the main inflorescence types. left: normal ('White Mite'), right: bud ('Anneliese').
Mentions: Breeding efforts in C. vulgaris primarily aim at a special type of its inflorescence, the so-called bud flowers (Fig. 1). Flowers of these plants do not open during the entire reproduction phase from August to December which makes them appear visually attractive for a long period of time when not many other flowering ornamental outdoor plants are available in the northern hemisphere. This phenotype is closely linked with and possibly caused by a lack of anthers. This connection, in turn, has a severe impact on breeding methods because interesting bud-flowering genotypes are only applicable as the female parent in crossings. In addition, there is only sparse information and hypotheses available concerning the inheritance of this trait. Therefore – and since C. vulgaris is a vegetatively propagated crop – breeding in C. vulgaris over the past few decades was to a large extent performed by selection of spontaneous mutations, rather than by systematic crossings (personal communications with breeders). The actual variety composition in Europe offers a mixture of normal flowering and bud flowering types (state: 01/2008) with main focus on the latter (~85%). Some special forms (e.g. 'Radnor' with filled flowers or 'Peace' as a multi-bracteate type) are present as well. However, due to the problems described above, the actual gene pool used in breeding of C. vulgaris is presumably quite narrow.

Bottom Line: In contrast, the system applied in lettuce, which itself applies pairwise comparisons using appropriate reference sets, proved functional with this species.The narrow gene pool detected in C. vulgaris may be the genetic basis for juridical conflicts between breeders.We successfully tested a methodology for identification of Essentially Derived Varieties in highly identical C. vulgaris genotypes and recommend this for future proof of essential derivation in C. vulgaris and other vegetatively propagated crops.

View Article: PubMed Central - HTML - PubMed

Affiliation: Heidepflanzen Peter de Winkel, Douvenberg 34, 47547 Goch, Germany. borchert@erfurt.igzev.de

ABSTRACT

Background: Variety protection is of high relevance for the horticultural community and juridical cases have become more frequent in a globalized economy due to essential derivation of varieties. This applies equally to Calluna vulgaris, a vegetatively propagated species from the Ericaceae family that belongs to the top-selling pot plants in Europe. We therefore analyzed the genetic diversity of 74 selected varieties and genotypes of C. vulgaris and 3 of Erica spp. by means of RAPD and iSSR fingerprinting using 168 mono- and polymorphisms. The same data set was utilized to generate a system to reliably identify Essentially Derived Varieties (EDVs) in C. vulgaris, which was adapted from a method suggested for lettuce and barley. This system was developed, validated and used for selected tests of interest in C. vulgaris.

Results: As expected following personal communications with breeders, a very small genetic diversity became evident within C. vulgaris when investigated using our molecular methods. Thus, a dendrogram-based assay to detect Essentially Derived Varieties in this species is not suitable, although varieties are propagated vegetatively. In contrast, the system applied in lettuce, which itself applies pairwise comparisons using appropriate reference sets, proved functional with this species.

Conclusion: The narrow gene pool detected in C. vulgaris may be the genetic basis for juridical conflicts between breeders. We successfully tested a methodology for identification of Essentially Derived Varieties in highly identical C. vulgaris genotypes and recommend this for future proof of essential derivation in C. vulgaris and other vegetatively propagated crops.

Show MeSH